From mboxrd@z Thu Jan 1 00:00:00 1970 From: roel.kluin@gmail.com (Roel Kluin) Date: Fri, 13 Nov 2009 11:37:34 +0100 Subject: [PATCH] pxa: make index mfp unsigned in mfp_read() and write() In-Reply-To: References: <4AFAE0DA.6040300@gmail.com> Message-ID: <4AFD36EE.6030509@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Ensure we do not read/write outside array boundaries with a negative index. Signed-off-by: Roel Kluin --- On 13-11-09 08:03, Eric Miao wrote: > On Thu, Nov 12, 2009 at 12:05 AM, Roel Kluin wrote: >> When signed, it is possible in theory to pass a negative mfp, >> and read/write outside the array bounds. >> I did not observe the passing of a negative mfp anywhere so this >> can be considered as a cleanup. Alternatively I could introduce >> a `mfp < 0' check in mfp_{read,write} instead if desired. >> > > I'd prefer to have a check in mfp_{read,write} instead. ok, diff --git a/arch/arm/plat-pxa/mfp.c b/arch/arm/plat-pxa/mfp.c index 9405d03..be58f9f 100644 --- a/arch/arm/plat-pxa/mfp.c +++ b/arch/arm/plat-pxa/mfp.c @@ -207,7 +207,7 @@ unsigned long mfp_read(int mfp) { unsigned long val, flags; - BUG_ON(mfp >= MFP_PIN_MAX); + BUG_ON(mfp < 0 || mfp >= MFP_PIN_MAX); spin_lock_irqsave(&mfp_spin_lock, flags); val = mfpr_readl(mfp_table[mfp].mfpr_off); @@ -220,7 +220,7 @@ void mfp_write(int mfp, unsigned long val) { unsigned long flags; - BUG_ON(mfp >= MFP_PIN_MAX); + BUG_ON(mfp < 0 || mfp >= MFP_PIN_MAX); spin_lock_irqsave(&mfp_spin_lock, flags); mfpr_writel(mfp_table[mfp].mfpr_off, val);